This air quality monitor helps you to track real-time CO2 levels wherever you go indoor & outdoor. Our pocket sized monitor is the slimmest and handy device that you can easily fit into your pocket. Multiple User-Interfaceslogo Displaying the real-time CO2 levels in the form of both the emoticon and numerical screens. Green, yellow, and red color representation. https://www.pranaair.com/air-quality-monitor/pocket-co2-monitor/